1. Field of the Invention
The present invention relates generally to a portable terminal having a motion detection function and a motion detection method therefor, and in particular, to a portable terminal having a motion detector for measuring accelerations of the portable terminal along its' X-, Y- and Z-axes, and a controller for calculating rotation angles of the portable terminal along the X- and Z-axes in a current posture of the portable terminal with respect to the X- and Z-axes in a basic posture of the portable terminal using the acceleration measurements, converting the accelerations along each axis to basic-posture accelerations along each axis using the rotation angles, and recognizing the motion of the portable terminal based on the basic-posture accelerations along each axis, and a motion detection method for the portable terminal.
2. Description of the Related Art
In recent years the use of mobile phones and PDAs (Personal Digital Assistants) have increased dramatically. These portable terminals find their use in increasing applications including image capturing with an equipped digital camera, satellite broadcasting reception, and games, beyond basic phone calls or scheduling.
In addition, such portable terminals have been made to include a motion detector so that the motion or inclination of a handset itself can be used as a form of manipulation, instead of pressing a keypad with buttons or touching a touch screen.
Hence, without pressing the digits of a phone number one by one on the keypad, a call can be placed by making a motion with the portable terminal.
For instance, a spam call or a spam message may be deleted by shaking the portable terminal with a motion detector twice up and down. A call may be placed by short dialing using a digit if a user draws the digit with the portable terminal. In addition, the user can play a percussion instrument like a tambourine or can create a variety of beatbox effects by shaking the portable terminal. Particularly, drawing ‘0’ or ‘1’ with the portable terminal can invoke an utterance such as “oh yes” or “oh no” in on-line games or in using emoticons. Furthermore, songs can be selected by means of a simple up and down motion of the portable terminal during use of an MP3 function.
Conventionally, the user makes an intended motion with the portable terminal, while maintaining the portable terminal in a basic posture, for motion detection. This conventional motion detection method neglects the fact that the portable terminal takes a different posture in a three-dimensional space depending on the user's holding the portable terminal in his hand.
The basic posture refers to a posture in which the user is supposed to maintain the portable terminal when making a motion with the portable terminal, for motion detection in the portable terminal.
The above motion detection method neglects other postures of the portable terminal, increases user inconvenience and decreases a motion detection rate.